Method for mounting a drum as well as a drum and an axle for a brush roller

ABSTRACT

A drum for a brush roller comprised of a plurality of arcuate shaped segments with circumferentially projecting shoulders at their ends. The shoulders have outer edges that contact the adjacent segments and have respective inwardly and outwardly facing surfaces which in adjacent segments overlie and are attached together. Each segment has radially spaced double walls with sufficient rigidity and has reinforcement. The outward side of each segment is provided with a plurality of protruding beams defining U-shaped channels between them. An axle includes the drum with end plates and projecting shafts at each end. Also, a method of assembling the drum wherein the edges of the shoulders are brought against adjacent segments and the shoulders have their respective inwardly and outwardly facing surfaces overlying and fastening elements extend through the shoulders.

TECHNICAL FIELD

The invention relates to a drum as axle in a brush roller. Brush rollersare used for cleaning large flat surfaces and also in industrial contextfor deburring, polishing or roughening surfaces or edges.

BACKGROUND ART

It is well known that axles for brush rollers, particularly brushrollers used in road cleaning machines, are difficult to manufacture.These brushes generally have a length of between 1.5 to 4 meter and adiameter of between 700 and 1800 mm. The brushes rotate at a speed ofbetween 400 and 1000 r/m.

The traditional method of manufacturing the axle of a brush roller is toattach axial holders on a steel pipe or rod, at the periphery of thepipe. Various types of brush magazines are then fitted in these holders.These axial holders are generally made of extruded aluminium. Othercomponents included in such a brush roller are various forms of keyjoints and spacers. The steel pipe and spacers are welded together withknown precision. A large number of holes for attachment bolts must alsobe drilled and threaded in the steel pipe. This vast number ofcomponents entails high storage costs for material as well as expensivemachining costs.

Commercial alternatives available are to design the axle of the brushroller as a fully extruded aluminium section. One problem is that thedie used for the extrusion is limited as to size so that only certainmaximum diameters can be produced. Furthermore, these extruded aluminiumsections are extremely heavy since the material is thick, and it isimpossible to reduce their mass by inserting cavities. A considerabledrawback when extruding aluminium sections is the banana shape thesection acquires on the cooling bed. A section that is 4 meter in lengthmay have a curvature of 4 mm or more. This curvature entails extra workat the dynamic balancing.

It is also known through U.S. Pat. No. 3,134,123 and U.S. Pat. No.3,862,463 to make the cylindrical axle of the brush roller in segments,which are joined together and anchored, to hub members situatedcentrally at the ends of the axle. The segments are in the form ofthin-walled sections, which are not reinforced in axial direction, andthe axle is therefore limited in both length and diameter. This methodof constructing the axle of a brush roller does not permit themanufacture of long axles, e.g. 4 m, nor axles having large diameter,e.g. 1200 mm, because of the unbalance occurring at the revolutionspeeds involved. U.S. Pat. No. 3,134,123 also indicates that theembodiment shown in FIG. 3 constitutes a self-supporting construction.However, this construction is extremely expensive since the dovetailjoints of the sections cannot be manufactured without after-working,with the tolerances necessary if the joints are to be free from play.Furthermore, the dovetail form according to U.S. Pat. No. 3,134,123 musthave a certain play to enable one section to be axially inserted intoanother section, and this per se results in play in the construction.

OBJECT OF THE INVENTION

The object of the invention is to solve the problems mentioned above andto improve a drum in the axle of a brush roller so that the axle becomessimpler and less expensive to manufacture, as well as being lighter,which contributes to increased stability at the bearing housings of theaxle.

Another object of the invention is to provide a drum for the axle of abrush roller which drum, under dynamic loading, behaves as a rigidcylinder.

A further object of the invention is to provide a drum for a brushroller with relatively large diameter and length, which can be producedfrom extruded aluminium sections and which, after assembly, performsentirely free from play and with a rigidity equivalent to a homogenousbody, e.g. a cylinder.

SUMMARY OF THE INVENTION

The objects stated above are achieved and the drawbacks eliminated bymeans of the present invention as defined in the claims.

The method for assembling a drum according to the inventive concept isthat the drum forms a part of an axle and that the axle constitutes apart of a brush roller. Characteristic of the assembly is that an axleconsists of a drum on which an end plate with two shaft ends have beenmounted.

The drum preferably has circular cross section. A plurality of axial,preferably U-shaped channels are arranged at the periphery of the drum.A normal axle has 16 channels but the number of channels may be eithermore or fewer. The drum is preferably made from four segments of extrudealuminium sections.

The number of segments is in no way limited to these four segments butmay vary from two or more, e.g. 2, 4, 6 or 8. An even number of sectionsis preferable in order to achieve dynamic balance in the simplest mannerat rotation. The segments exhibit an outer arc shape. Four segments, forinstance, are fitted together to form a drum. Each segment has a firstedge part with a first shoulder and a second edge part with a secondshoulder.

Assembly of four segment sections to a drum is as follows:

In a first step each segment is arranged so that the edge portion of thefirst shoulder and/or the edge portion of the second shoulder are incontact with the second or first contact surface, respectively, of anadjacent segment. This ensures that the drum will always have the samediameter. A space between the various segments may cause unbalance. Thecontact surfaces between the shoulders of the segments are flat so as toobtain the greatest possible contact area without having to machine thesurfaces. Alternatively the contact surfaces of the shoulders may beprovided with pins and recesses in order to a greater extent to take uptangential shear stress between the segments.

A variant of the shape of the segments is to arrange two adjacentsegments with the lower side of the second shoulder of a first segmentin contact with the upper side of the first shoulder of a secondsegment.

This is done when the shoulders of the segments are at different levels,i.e. radial distance from the axis of rotation of the axle. Analternative embodiment is the use of two differently shaped segments,alternate segments being identical, i.e. the shoulders on alternatesegments are at equal radial distance from the inner arc.

Another factor is that each section is curved at the extrusion. Bydividing the drum into segments, the curvature of the segments will becompensated and the drum becomes straight. At one and the same extrusionprocess each rod will be cooled in the same way and each will acquiresimilar defects.

A second step entails drilling or drilling and threading through-holesin radial direction, e.g. through the first, outermost shoulder as aclearance hole and through the second, innermost shoulder as a threadedhole, in each segment. Two or more holes are drilled along the segmentsin each shoulder, at equal or different distances from each other.

The third step entails passing an attachment element, a bolt or a screwand nut, through each hole. This screw joint ensures complete freedomfrom play, which is necessary if a brush roller 2.5-6.0 meter in lengthis to be balanced dynamically and then withstand a continuous speed ofrevolution of up to 1200 rpm.

When the drum is mounted on the axle, a circular plate with aconcentrically arranged shaft end is fitted on the end portions of thedrum. Congruence exists between every or every other segmentincorporated in a drum. The advantage of having only one shape for thesegments in the drum is to save costs.

The segments incorporated in a drum exhibit the followingcharacteristics:

the segments consist of extruded aluminium sections;

a segment exhibits an outer arc form;

each aluminium section is provided on its upper side with two or more,preferably four, radially protruding beams;

a U-shaped channel is formed between two adjacent beams;

each segment has a first shoulder and a second shoulder.

In one embodiment the upper side of the first shoulder and the lowerside of the second shoulder of a segment preferably have flat surfaces.

The segments are also made double-walled, one or more cavities beingformed in each segment. In a segment with two cavities, these cavitiesare separated by radially reinforced spacers extending axially along theentire length of the segment. The U-shaped channels of the segment arealso situated radially in relation to the imagined central axis of thedrum.

BRIEF DESCRIPTION OF THE DRAWINGS

One embodiment of the invention is shown schematically in theaccompanying drawings in which

FIG. 1 shows an axle with its drum and two shaft ends,

FIG. 2 shows an end part of a drum including a number of brush magazinesinserted into slots,

FIG. 3 shows an embodiment of a brush magazine

FIGS. 4A-B show a segment

FIG. 5 shows a section from FIG. 3 through a join between two segmentsrevealing hole and bolt.

FIG. 6 shows a view A—A in FIG. 1 of an end part of the axle of a brushroller.

DESCRIPTION OF THE INVENTION

FIG. 1 illustrates an axle 1 seen from the front, built up of a drum 2and two shaft ends 3, 4. Each shaft end 3, 4, which may have the form ofpart of a spline joint, is mounted on a torque transmitting plate 50which in turn covers the end part 22 of the drum 2. Two shaft ends 3, 4,each with a-plate 50, together with a drum 2, constitute the axle 1 of abrush roller.

FIG. 2 shows an end part of the drum 2, the drum 2 in this embodimentcomprising four segments 7.1, 7.2, 7.3, 7.4. The drum 2 is formed by thefour segments 7.1, 7.2, 7.3, 7.4 after assembly. The segments 7.1, 7.2,7.3, 7.4 are produced from an extruded aluminium section. Each segment7.1, 7.2, 7.3, 7.4 is provided on its upper side 8 with four radiallyprotruding beams 9.1, 9.2, 9.3, 9.4. In order to reduce manufacturingcosts, the segments 7.1, 7.2, 7.3, 7.4 are congruent with each other.

In a drum 2 assembled from four segments 7.1, 7.2, 7.3, 7.4 there aresixteen U-shaped channels 10.1 . . . 10.16, arranged so that a U-shapedchannel 10.2 is produced between two adjacent beams 9.1, 9.2. Similarly,the channels 10.1, . . . 10.16 are arranged between the adjacent beams9.1, . . . 9.16. Rows of brush magazines 13 in which brushes are fitted,are shown in the U-shaped channels 10.8 . . . 10.11. Eight circular,threaded holes 21.1, . . . 21.8 intended for use when assembling theplate 50 with its shaft ends 3, 4 to the end part 22 of the drum 2 arealso arranged axially in each segment, preferably in the area below abeam near the ends of the segment. The drum is arranged to rotate aboutits central axis 12.

FIG. 3 shows an embodiment of a brush magazine 13 comprising a holder 14for five brushes with card wire 15, pressed into a plastic holder 16.

FIGS. 4A and 4B show an individual segment 7.1 with its extrudedaluminium section, seen from the end. When an aluminium section 7 isextruded through a die, all the holes in the die will give the aluminiumsection 7 an elongate shape. The pattern of holes in a die correspondswith the cross section of the section. In order to reduce the cost atmanufacture, as well as the weight, and to increase the rigidity of thesection 7, the section is provided with a number of cavities 20.1-20.6,four of which are situated in the beams 9.1, . . . 9.4, and two in thesection 7. The two cavities 20.2, 20.4 in the section are formed by thesection having double walls and the cavities being separated by radiallyreinforced spacers 60 extending axially along the entire length of thesegment. In this example there are two more holes—the two circular,threaded holes 21.1, 21.2 intended for use when assembling the plate 50with its shaft ends 3, 4 to the end part 22 of the drum 2, see FIG. 1.Each beam 9.1 . . . 9.4 in the segment 7.1 exhibits a first side part25.1 and a second side part 25.2, each with a longitudinal slot 26.1,26.2. Each slot 26.1, 26.2 in each beam 9.1, . . . 9.4, is at the samedistance from the central point 12 of the drum. The openings of theslots 26.1, 26.2 face the U-shaped channel 10.1 . . . 10.16. Theopenings 11 of the U-shaped channels 10.1 . . . 10.16 face away from thecentre 12 of the drum 2.

The outwardly facing surfaces 27.1 . . . 27.16 of the beams 9.1, 9.2when the segments 7.1 . . . 7.4 are assembled to a drum 2, are at atangent to a circumscribed circle 28. Each segment 7.1, 7.2, 7.3, 7.4has an outer arc shape 28A. One segment 7.1 in this example shows aninwardly facing surface 29 which also has an arc shape. Both thecircumscribed circle 28 and the inwardly facing arc-shaped surface 29have the same radial centre 12. A first shoulder 35 is arranged on thesection 7, tangentially outside the first beam 9.1, and a secondshoulder 36 is arranged on the section tangentially outside the fourthbeam 9.4. The surfaces of the upper side 37 of the first shoulder 35 andthe lower side 38 of the second shoulder 36 are preferably flat but mayalso assume an arc shape with a common radius 39. The centre of theradius 39 is at the centre 12 of the drum. The width “b1-b2”, i.e. thedistance from the inner corner b2 between the upper side 37 of theshoulder 35 and a first radial contact surface 40 on the first beam 9.1to the outer corner b1 of the shoulder 35 is preferably equal to thewidth “b3-b4”, i.e. the distance from the inner corner b3 between thelower side 38 of the second shoulder and a second radial contact surface41 below the fourth beam 9.4 to the outer corner b4 of the shoulder 36.

The outside of the preferably upwardly directed part at the upper side37 of the first shoulder 35 is thus designated a first contact surface40. The outside of a preferably radially downwardly directed part at thelower side 38 of the shoulder 36 is corresponding designated a secondcontact surface 41.

The first shoulder 35 is provided with a first edge part 42. This edgepart 42 extends from the lower side 29 of the shoulder 35 to its upperside 37. The second shoulder 36 is provided with a second edge part 43extending from the lower side 38 of the shoulder 36 to the upper side 44of the shoulder 36.

Assembly of the drum 2 is performed as follows:

a) four segments 7.1, 7.2, 7.3, 7.4, FIGS. 4A, 4B, are arranged close toeach other as shown in FIG. 2 in such a way that the upper side 37 ofthe first shoulder 35 of a segment 7.1, 7.2, 7.3, 7.4 is brought intocontact with the lower side 38 of a second shoulder 36;

b) the first shoulder 35 of each segment 7.1, 7.2, 7.3, 7.4 and itsfirst edge part 42 are brought into contact with the second contactsurface of adjacent segments 7.1, 7.2, 7.3, 7.4, see FIG. 2;

c) the second shoulder 36 of each segment 7.1, 7.2, 7.3, 7.4 and itssecond edge part 43 are brought into contact with the first contactsurface 40 of adjacent segments, see FIG. 2;

d) an alternative to b) and c) is for either a first edge part 42 to bein contact with a second contact surface 41 or a second edge part 43 tobe in contact with a first contact surface 40;

e) holes 45, 46 are drilled and threaded in radial direction, FIGS. 4A,4B, through each first 35 and second shoulder 36.

f) a plurality of holes 45, 46 are drilled at equal or different axialdistance from each other;

g) an attachment element 47, FIG. 5, bolt, is arranged through each hole45, 46 in such a manner that a friction joint is obtained between theshoulders 35, 36 at the contact surface 37, 38.

FIG. 5 shows a section through a joint in FIG. 2 between two adjacentsegments 7.1, 7.2. The section shows that the segments have beenassembled using a screw joint, the second shoulder 36 of one segment 7.1having a throughhole radially-aligned with a threaded hole through thefirst shoulder 35 of the second segment 7.2. An attachment 47 in theform of a bolt, i.e. a machine screw, is screwed through these holes.The flat contact surfaces 37, 38 are thus pressed against each other,see FIG. 2. The upper side 44 of the shoulder 36 is also flat in orderto provide the best possible contact surface for the attachment element47.

FIG. 6 shows a view A—A in FIG. 1 with part of the plate 50 removed. Thefigure shows the end of the axle 1 with its shaft end 3 arrangedconcentrically with the plate 50. Holes 52.n are arranged at theperiphery 51 of the plate 50, where n=1, . . . 8, for a secondattachment element 53 in the form of an axially fitted bolt. Thedistance between the holes 52.1 . . . 52.8 corresponds to the distancebetween the threaded holes 21.n, where n=1, . . . 8, at the end part 22of the drum 2.

Assembly of the plates 50 with their shaft ends 3, 4 to the drum 2 isperformed as follows:

a) a shaft end 3, 4 and its torque-transmitting plate 50 is arranged ateach end part 22 of the drum 2;

b) the shaft ends 3, 4 with plate 50 are arranged concentric with theend part 22 of the drum 2;

c) the attachment element 53 is screwed through the holes 52.1, . . .52.8 in each plate 50 and into the holes 21.1, . . . 21.8 in the endpart 22 of the drum 2.

The invention is not limited to the example described but can be used inall drums built up of segments to be used as part of an axle where eachsegment is in the form of an extruded section and where each segment hastwo shoulders that are united with an attachment element. The inventionis not limited to a certain number of segments but applies to allsegments amounting to two or more. Neither is the invention in itswidest scope limited to the drum assuming the shape of a cylinder. Itmay also assume the shape of an equilateral polygon.

What is claimed is:
 1. A drum for a brush roller, wherein the drum iscomprised of a plurality of segments, each segment having opposite firstand second ends with respect to a rotation direction of the drum, thefirst end of each segment cooperating with the second end of theadjacent segment and the adjacent segments are joined to form a drum;each segment having an upper side which is outwardly facing when thesegments are joined; a plurality of outwardly protruding beams on theupper outwardly facing side, the beams being shaped and placed to definea respective U-shaped channel between adjacent beams on the segment;each segment having a double wall, with an inward wall toward an innerside of the segment, an outward wall toward the upper side of thesegment, and the inward and outward walls being sufficiently rigid forthe assembled segments to form a fully self-supporting drum when thesegments are joined at the respective cooperating first and second endsof adjacent segments; a torque transmitter connected to the drum forrotating the drum about an axis.
 2. The drum of claim 1, wherein thereare four outwardly protruding beams on each of the segments.
 3. The drumof claim 1, further comprising reinforcing spacers between the doublewalls of the segments.
 4. The drum of claim 1, wherein the segments areshaped so that at least two of the segments are congruent.
 5. The drumof claim 1, wherein the upper side of each of the segments defines anouter arcuate shape, and the segments are of such circumferential lengthand are of such number that when the segments are joined with the firstside of one segment adjacent the second side of the adjacent segment,the drum has a cylindrical drum shape.
 6. The drum of claim 5, whereineach segment has a respective first shoulder projecting outwardly fromthe first end and has a respective second shoulder projecting outwardlyfrom the second end, with the first and second shoulders beingrespectively so placed on the ends of the segments that the firstshoulder has an upper outwardly facing first surface and the secondshoulder has a lower inwardly facing second surface.
 7. The drum ofclaim 6, wherein the outwardly facing first surface of the firstshoulder of one segment has resting on it the inwardly facing secondsurface of the second shoulder of the adjacent segment.
 8. The drum ofclaim 7, wherein the first and second surfaces are flat and orientedparallel.
 9. The drum of claim 8, further comprising fastening elementsbetween the first and second shoulders at adjacent segments for joiningthe adjacent segments.
 10. The drum of claim 6, wherein there are aplurality of the segments, the segments are extruded, are of arcuateshape and are of identical length.
 11. An axle for a brush roller,comprising a drum according to claim 6, the drum having opposite axialends; a respective torque transmitting plate arranged concentrically inrelation to and connected to each of the axial ends of the drum; and arespective shaft and projecting from each of the torque transmittingplates.
 12. The drum of claim 7, wherein the shoulders have respectiveouter edges and each of the outer edges of the shoulders rests againstthe adjacent segment.
 13. The drum of claim 1, wherein each segment hasa respective first shoulder projecting outwardly from the first end andhas a respective second shoulder projecting outwardly from the secondend, with the first and second shoulders being respectively so placed onthe ends of the segments that the first shoulder has an upper outwardlyfacing first surface and the second shoulder has a lower inwardly facingsecond surface.
 14. The drum of claim 13, wherein the outwardly facingfirst surface of the first shoulder of one segment has resting on it theinwardly facing second surface of the second shoulder of the adjacentsegment.
 15. The drum of claim 1, wherein each of the segments is anextruded aluminum section including the respective shoulders at theopposite first and second ends.
 16. The drum of claim 1, wherein thereare an even number of segments.